Below is the Brandy Lake watershed.   Part of the lake study (more to come) 2002 and 2003 Initiated by Jane Evans who started the BLA.

Jim Cormack did bi-weekly test from May to November for two years.

“Quote” The calculations suggest that the internal load represents
approximately 35% of the annual load to Brandy Lake, with the watershed (47%) and
atmosphere (2%) contributing nearly half of the total load. The load from shoreline
development is estimated at 16% of the total annual load In 2003

Subsequent to this study..there are about eight (8) beaver dams in inlet stream 1.  Jim Cormack and myself paddled from Falkenburg Road pipes to the Lake several years ago to count